Scion The upper cultivar portion used in grafting, selected for its flowers, growth habit, or desired traits and joined to a rootstock. Related Articles: Glossary: GraftPropagating Plumeria through grafting to combine traits from different plants.Glossary: Bud GraftingBud grafting, also known as "budding," is a horticultural technique used to propagate plants by joining the bud of one plant (the scion) to...Glossary: Graft Uniongraft jointM3 – Grafting Fundamentals (Field Book)